DNA, RNA, and PROTEIN SYNTHESIS DNA, genome, instructions, blueprint, chromosomes, genes All MEAN DNA!!!! THEY ALL HAVE TO DO WITH DNA DNA is a molecule that carries the instructions for how to make an organism

DNA is organized into bundles called CHROMOSOMES. Humans have 46 chromosomes CHROMOSOMES have segments on them that code for certain qualities (eye color, hair color) The segments or areas are called GENES and they code for all of an organisms TRAITS or characteristics

DNA is found in, and cannot leave the nucleus (too big). Since it has such important information it is guarded in the nucleus of cells. DNA carries information from parents to offspring (kids) Gametes = sperm/egg The types of cells that carry information from parents to offspring are called gametes. Gametes are sex cells, sperm and egg. Humans and their cells have 46 chromosomes. 23 come from mom (egg), 23 come from dad (sperm).

2.Deoxyribose sugar group De=without Oxy= Oxygen Ribose=sugar 3.Phosphate group 1.Nitrogen base DNA (DeoxyRiboNucleic Acid) is made up of nucleotides that repeat. Each nucleotide is made of 3 parts:

There are 4 nitrogen bases: Adenine (A), Cytosine (C), Thymine (T), and Guanine (G) The sequence of nitrogenous bases determines the traits that will appear. The sequence of codons (3 letter codes)

DeoxyribonucleicAcid (DNA) the Double Helix The sugar and phosphate groups make up the outside part of the ladder. The base pairs make up the inside “steps” of the ladder.

Watson & Crick were the first to successfully show the structure of DNA. (Double Helix) According to Chargaff’s rule: A pairs to T C pairs to G The bases are found in a 1:1 ratio adenine bonds with thymine guanine bonds with cytosine The two halves of the DNA strand are called complementary because they pair together

Reasons why cells divide The cell becomes too big. The larger a cell becomes, the more demands the cell places on its DNA Also, a larger cell has more trouble keeping up with the needs of the cell Cells will continually divide during the growth of an organism. Mitosis/Cell Division

The process by which cells divide Before a cell divides it must make an exact “copy” or “replica” of it’s DNA. The copy or replica of DNA is made during the S- Phase of Interphse. After Interphase is complete the cell can divide by Mitosis. Cell Division or Mitosis allows organisms to grow larger while cells remain small

Replication = First the DNA unzips

Next new nucleotides are added to each side until 2 identical strands are made (remember A to T and C to G) Original Strand Opens/Unzips The “new” strand will line up in here Original Strand “New” Strand

Replication / Mitosis Mitosis results in 2 identical “daughter” cells Each has all 46 chromosomes An exact copy of the original

1. DNA is the “code” – the instructions for how to make PROTEINS, the main structures of the body. 2. DNA is in the nucleus of the cell, but PROTEINS are made in the cytoplasm by RIBOSOMES. Remember, DNA cannot leave the nucleus. We need a way to get the DNA out of the nucleus to the ribosomes. Protein synthesis happens in 2 steps. Protein Synthesis

1.The DNA strand in the nucleus separates. 2.In order to get “BIG” DNA out of the nucleus we must re-write it as a messenger (RNA). 3.This RNA acts as a messenger (mRNA) that carries the instructions out of the nucleus to the ribosome 4.When the genetic code (DNA) is copied/re-written to messenger RNA, mRNA this is called transcription. Protein Synthesis Step 1: Transcription

RNA (RIBO-NUCLEIC-ACID) RNA has Ribose as its sugar instead of Deoxyribose It is Single Stranded, meaning that it is only half of the ladder (double helix) RNA has Uracil as a base instead of Thymine Guanine – Cytosine Adenine – Uracil (no T, Thymine in RNA)

Step 2: Translation 1.mRNA attaches to a RIBOSOME AMINO ACIDS 3 letter CODONS on mRNA tell what the AMINO ACID will be 2.Every 3 letter group on a strand of mRNA is a CODON which codes for an AMINO ACID - amino acids are the building blocks of proteins (20 of them; 9 are essential) 3. The RIBOSOME “reads” the mRNA, then transfer RNA (tRNA) brings the correct AMINO ACID to form the protein chain We translate 3 letter codons into an amino acid chain.

What 2 amino acids do these CODONS code for?

The Central Dogma

Mitosis vs. Meiosis Mitosis results in 2 identical “daughter” cells Each has all 46 chromosomes Meiosis results in 4 genetically Different haploid cells. Haploid means half The Gametes (sex cells) have ½ the info

Name Date Biology class pd. Write about DNA. What is DNA? What is the structure and parts of DNA? How is DNA used to make proteins in protein synthesis